Terminal 2E, Roissy Airport, Paris

Since the opening of the concrete passenger-handling rotunda in 1974, the airport has grown rapidly and now forms a major transfer point between land and air traffic. The latest development, a passenger strip 650m long and 134m wide, forms a linear extension to Terminal F and should reduce the present handling costs by 10per cent. The structure is divided by roof-light bands into a series of straight sections 72m in length (the maximum aircraft wingspan). The curvature on plan is achieved by setting the sections at a slight angle to each other. The building consists of four-metre-wide concrete double-curved arches articulated into three segments across their span and perforated by a grid of square openings. The load-bearing system is visible only on the outside, where the horizontal loads in the 30cm concrete shell are borne by elegantly curved steel sections at the base of the arches. The central segment at the crest of the shell simply rests on the base segments. At the sides, the building is enclosed in a transparent glass skin, while the opaque crest is covered with stainless-steel sheeting. The structural system thus helps to reduce thermal gains internally. The striking spatial quality and the sense of “béton brut” in the interior were heightened by installing all mechanical services in the plane between the inner and outer skins. Ventilation is effected by tubes plugged into the glazed openings.